Adobe Camera RAW
I became a designer as an excuse to spend my days playing with photographs. After trying an SLR camera it was obvious I could get good at this. I found a way to scan film so my photos could could edited using state-of-the-art-in-1994 Photoshop version 2.5.
Rethinking the Adobe Photo Editing Workflow – Pt 2. How to use Photoshop Smart Objects to encapsulate your work, applying almost any edit non-destructively.